The present invention relates to an inkjet recording apparatus comprising an inkjet recording head for discharging ink droplets, and more particularly relates to the structure of the inkjet recording head.
There have conventionally been provided inkjet recording apparatuses for recording an image on a recording medium by discharging ink droplets onto the recording medium. The ink droplets are discharged from an inkjet recording head incorporated into an inkjet recording apparatus. The inkjet recording head comprises a plurality of nozzles for discharging ink droplets, and an actuator such as a piezoelectric element, an electrostrictive element, or a heating element. With local boiling of an ink caused by bending or heat of the actuator, ink droplets are discharged from the nozzles. This inkjet recording head is mounted on a scanning carriage that moves reciprocally in directions orthogonal to the transport direction of the recording medium. The recording medium is transported by a predetermined width of line feed in the transport direction, and the scanning carriage is moved every time line feed is performed. With the movement of the scanning carriage, the inkjet recording head discharges ink droplets from the nozzles in a predetermined timing. Consequently, an image is recorded on the recording medium.
In the inkjet recording apparatus, it is important to certainly discharge ink droplets from all the nozzles. The reason for this is that, if any one of the nozzles is clogged with a foreign object or has an air bubble, a discharge defect of ink droplets occurs and the image quality deteriorates. In order to prevent clogging of nozzles and entry of an air bubble into the nozzles, purging or flushing of the inkjet recording head is generally performed. However, these operations are not intended to directly detect the clogging of nozzles or entry of an air bubble. Therefore, conventionally, there were proposed inkjet recording apparatuses capable of actively detecting the clogging of nozzles (see Japanese Patent Applications Laid-Open No. 2003-191463 and No. H03-202354 (1991)).